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When to Plant Cowpeas in Harris County, TX

Harris County, Texas Zone 9b May

Harris County, Texas gardeners: here's your May plan

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Harris County, Texas.

Avg. last frost February 14
Avg. first frost December 4
Soil temp (4") 77°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Pick cowpeas

    If you can't use it all right away, check the food-preservation section of your planner.

Get ahead of June
  • First harvests: cowpeas

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Cowpeas (black-eyed peas) are a heat-loving legume that fixes nitrogen in the soil. They are drought-tolerant and produce protein-rich pods in hot conditions.

Harris County, Texas is in USDA Zone 9b. The average last spring frost is February 14 and the first fall frost is December 4, giving you a growing season of approximately 293 days.

At an elevation of 390 feet, Harris County receives approximately 67.7 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 102°F, so Cowpeas may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Cowpeas will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Cowpeas root diseases.

Harris County, TX (Zone 9b) Year-round
293 days
Last Spring Frost February 14
293 growing days
First Fall Frost December 4

Harris County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.3-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (188 days to spare)
Transplant: Feb 6 🍅 Harvest: Apr 10 – May 22
Recommended (50%) ✓ Fits season (188 days to spare)
Transplant: Feb 14 🍅 Harvest: Apr 18 – May 30
Safe Start (90%) ✓ Fits season (184 days to spare)
Transplant: Mar 8 🍅 Harvest: May 10 – Jun 21

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Harris County

How your county's soil matches Cowpeas's growing requirements.

Soil pH

Your soil pH (5.3–6.5) overlaps with Cowpeas's range (5.5–7.0), though not a perfect match.

Soil Texture

Sandy soil in Harris County warms quickly in spring but drains fast. Cowpeas will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Cowpeas.

How to Plant Cowpeas

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Succession Planting Cowpeas

5
successive plantings in your 293-day season

Sow every 6.9 weeks. Last sowing by Sep 05 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Cowpeas

Cowpeas needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Cowpeas Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 2.2" 2.7" 0" ✅ Rainfall sufficient
Mar 2.2" 3.8" 0" ✅ Rainfall sufficient
Apr 2.2" 7.4" 0" ✅ Rainfall sufficient
May 2.2" 10.1" 0" ✅ Rainfall sufficient
Jun 2.2" 10" 0" ✅ Rainfall sufficient
Jul 2.2" 9.6" 0" ✅ Rainfall sufficient
Aug 2.2" 8.5" 0" ✅ Rainfall sufficient
Sep 2.2" 6.3" 0" ✅ Rainfall sufficient
Oct 2.2" 3.9" 0" ✅ Rainfall sufficient
Nov 2.2" 2.2" 0" ✅ Rainfall sufficient
Dec 2.2" 1.6" 0.6" 💧 Light watering

Water needs are for active growing months only (Feb–Dec in Harris County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Cowpeas Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Cowpeas needs ~1,988 GDD — county provides 7,791 GDD Excellent fit

Cowpeas Planting Timeline — Harris County, TX

Cowpeas Planting Calendar

Activity When Date Range
Direct Sow February 21 Feb 21 – Mar 14
Harvest April 25 Apr 25 – Jun 6

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February Direct Sow
March Direct Sow
April Harvest
May Harvest
June Harvest
July
August
September
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 9b

📆 Growing Season

293 days in Harris County

Growing Tips for Cowpeas in Harris County

Direct sow Cowpeas outdoors after February 14 in Harris County when soil has warmed and frost danger has passed.

Sandy soil in Harris County dries quickly — mulch Cowpeas with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 102°F in Harris County, provide afternoon shade for Cowpeas and water deeply in the morning.

Common pests for Cowpeas in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow after soil is thoroughly warm. Do not over-fertilize with nitrogen as cowpeas fix their own. Harvest pods when they begin to dry on the vine for dry beans.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel
  • Onion

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cowpeas in Harris County, TX?

Harris County is in Zone 9b with an average last frost of February 14. Plan your Cowpeas planting based on this frost date — see the calendar above for exact timing.

What planting zone is Harris County, TX?

Harris County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 14 and first fall frost is December 4.

🌱

Your Harris County Garden Planner — Free

A 24-page printable planner built for Harris County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Harris County, TX. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.